Abstract: To inflate the balloon element on the distal end of a pulmonary artery catheter an improved gas syringe is provided which is both volume and pressure-limited so that the syringe is capable of discharging into the catheter no more than the maximum design gas inlet volume thereof while at the same reducing the maximum attainable pressure within the catheter to a predeterminable level substantially below that reached when a conventional volume-limited syringe of the same gas discharge capacity is used. The syringe volume delivery limitation is achieved by forming rearwardly disposed plunger stop members, or a suitable vent opening, in a sidewall portion of the syringe body. The pressure limitation is obtained by forming a pressure absorption zone which defines a substantially inextensible enlargement of the gas-receiving interior of the catheter.

Abstract: To inflate the balloon element on the distal end of a pulmonary artery catheter an improved gas syringe is provided which is both volume and pressure-limited so that the syringe is capable of discharging into the catheter no more than the maximum design gas inlet volume thereof while at the same reducing the maximum attainable pressure within the catheter to a predeterminable level substantially below that reached when a conventional volume-limited syring of the same gas discharge capacity is used. The syringe volume delivery limitation is achieved by forming rearwardly disposed plunger stop members, or a suitable vent opening, in a sidewall portion of the syringe body. The pressure limitation is obtained by forming a pressure absorption zone which defines a substantially inextensible enlargement of the gas-receiving interior of the catheter.

Abstract: A surgical device is disclosed which enables selective ventilation of the lungs of a patient. The device is inserted into the patient's respiratory passages and is employed in conjunction with a conventional breathing circuit which allows ventilation of either lung alone or both lungs simultaneously by pumping life supporting gases, typically including anesthetic agents, through the tube during surgery. The device comprises an elongated flexible tube split at its proximal end into left and right tubular extensions and having a curved distal end adapted to be inserted via the patient's mouth through the trachea into the left main stem bronchus. Inflatable cuffs surrounding the tube permit the lungs to be isolated from each other and from the atmosphere.